Impression tray



1924. 7 Dec 9 J. E. CRAHG 5 IMPRESS ION TRAY Filed March 24. 1924 IN V EN TOR A TTORNEYS Patented Dec. 9, 1924.

UNITED STATES JOSEPH E. CRAIG, OF GARY, INDIANA.

IMPRESSION TRAY.

Application filed March 24-, 1924. Serial :No. 701,481.

To aZZ whom art/may concern:

Be it known that I. JOSEPH E. CRAIG, a citizen of the United States, and a residentof Gary, county of Lake, State of Indiana, have invented a new and useful Improvement in Impression Trays, of which the following is a full, clear, and exact description.

My invention relates to improvements in impression trays, and it consists in the com binations, constructions, and arrangements herein described and claimed.

An object of my invention is to provide an impression tray for bridge and crown impressions, by means of which a split impression cast may be produced without discomfort to the patient. The ordinary type of split impression tray in use at the present time necessitates an awkward manipulation of forceps or other instruments in the mouth of the patient in moving the separable parts of the tray apart from one another.

A further object of my invention is to provide an impression tray of the type described in which the force applied for moving the separable parts away from one an- ,other is so directed as to cause strain upon that portion of the impression which will produce a clear cut split cast. A further object of my invention is to provide an impression tray of the type described in which all of the cooperating parts are assembled in a single unit, and therefore always ready for use. The type of impression trays employed at the present time consist usually of two or more entirely separable members, any one of which may be lost because of the diminutive size of the members, and thereby destroy the usefulness of the remaining parts.

A further object of the invention is to provide a device of the type described which is simple in construction, durable, and eflicient. for the purpose intended.

Other objects and advantages will appear in the following specification, and the novel features of the invention will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawings, forming part of this application, in which Figure 1 is a top plan view of an embodiment of my invention,

Figure 2 is a side elevation of the mechanismillustrated in Figure 1,

Figure 3 is a view of my improved impression tray with the separable members of the tray moved apart from one another, and

Figure 4 is a sectional view along the line 44 of Fig. .2.

In carrying-out my invention I make use of a handle member 1 having an opening 2 therethrough by means of which the device may be suspended from a hook or the like, and which also assists in the manual gripping of the handle.

A pair of cooperating andsepara'blememhers 3 and 4 :is pivotally supported upon the handle 1 by means of an eyelet rivet 5. These members 8 and 4 when moved into engagement with one another, (see Figure 1), form an impression tray having its remote side walls 6 and .7 respectively disposed in arcuate planes so as toconform with the natural arch of properly, aligned human teeth.

The adjacent walls 8 and 9 of the membersB and 4 respectively extend for a short distance upwardly from the bottom wall of these members, and are substantially concentric with the arch of the curved side walls 6 and 7. The purpose of the walls 8 and 9 is to extend upwardly into the impression cast formed in the tray and thereby provide a curf occupied by the walls 8 and 9, by means of which the cast may be readily split on a line in registration with the naturally aligned teeth about which the cast is formed. A slight aperture 10 is formed between, the adjacent edges of the members 3 and 4: at that part where the members join the handle 1. This is for the purpose of the introduction of an instrument 11 having a rectangular work engaging surface which when turned will occasion the movement of the members 3 and 4 apart from one another.

From the foregoing description of the various parts of the device, the operation thereof may be readily understood. In employing my improved impression tray, I move the cooperating members 8 and 4 into engagement with one another so as to form a tray having much the same appearance as the ordinary type of impression tray. Material for producing an impression cast is placed in the tray so formed, and the device is placed. so that the material in the tray may encompass the teeth of which the dentist wishes to obtain a cast. It Will be noted at this time that since the handle 1 is piv otally connected with the members 3 and 4, that the handle may be turned so as to readily accommodate the support of the device With the greatest amount of comfort to the various: portions of the mouth. If the cast is to be made of teeth in the region of the molars, then the handle 1 Will be pivoted to the right or to the left, depending upon which side of the mouth the teeth are disposed, and the angle at which the handle 1 is turned will depend upon how close to the front of the mouth the teeth are disposed.

When the mate-rial in the tray has properly set, the dentist will insert an instrument such as the instrument 11, heretofore described, and rotate the members 3 and 4 to move apart from one another, thus exerting pressure by virtue of the upwardly extending members 8 and 9 upon the adjacent Walls of the kerf formed in the lower wall of the cast. This force will cause the cast to be split at the proper place, thereby producing a perfect cast of the teeth or tooth.

I claim:

1. An impression tray of the type described comprising a handle member, a pair of cooperating members forming an impression tray permanently and pivotally supported uponthe outer end of said handle, said cooperating members being arranged to pivot laterally relative to said handle and to each other, whereby said members may be moved into engagement with one another or apart from one another at will.

2. An impression tray of the character described comprising a handle member, a pair of cooperating members forming an impression tray, said cooperating members being pivotally mounted upon said handle and arranged for, movement toward or away from one another, the movement of said cooperating members being eitected in a single plane, said cooperating members bein Ttlll'l'llfll. pro vided with registering recesses for the introduction of an instrument therebetween, whereby the members may be moved apart to split an impression :ast formed in said tray.

3. An impression tray of the character described comprising a handle, a pair ot cooperating members forming an impression tray pivotally supported upon said handle, said cooperating members arranged to be moved into engagement with one another or apart from one another at will, said cooperating members having their adjacent edges upturned to form relatively low side walls by means of which a kcrt is formed in the bottom wall of an impression cast formed in said tray, said cooperating members being further fashioner to permit the introduction of an instrument therebct-wcen whereby said members may be moved apart to split the impression cast formed in said tray.

JOSEPH E. CRAIG. 

